1. Field of Invention
The present invention relates to an active device array substrate and a display device. More particularly, the present invention relates to a thin film transistor array substrate and an E-ink display device.
2. Description of Related Art
E-ink display device was initially developed in 1970's. It is featured by a charged small ball with white color on one side and black color on the other side. The charged small ball rotates up and down to show different colors when the electrical field applied to small ball is changed. The second generation E-ink display device, developed in 1990's, is featured by a microcapsule which substitutes the conventional charged ball. The microcapsule is filled by color oil and charged white particles. By varying external electrical field allows white particles to move up or down. White color will be illustrated when white particles are moving up (getting close to reader) and the color of oil will be illustrated when white particles are moving down (getting away from reader).
In general, commercial E-ink display device comprises a front plane laminate (FPL) and a thin film transistor array substrate. Front plane laminate usually comprises a transparent cover, a transparent electrode layer and an E-ink material layer. The E-ink material layer comprises E-ink and supporting liquid. When the electrical field between each pixel electrode of the thin film transistor array substrate and the transparent cover of the front plane laminate is changed, E-ink will flow up or down to change optical property of each pixel.
Problems such as broken circuit and short circuit caused by contaminated particles and unexpected residual material are possible in manufacturing process which lead to low quality E-ink display device with dot defect or line defect. Therefore, it is very necessary to avoid such problem in order to improve the quality of E-ink display device.